For magnetic recording, erasing, and/or reproducing equipment, various techniques have been used to bring a recording medium into contact with a magnetic read/write head. Either the recording medium is pressed against the read/write head, or the read/write head is pressed against the recording medium. The latter approach has proven especially advantageous for relatively rigid recording media, e.g. magnetic cards, since the read/write head can then, with corresponding guides, also follow a varying surface contour of the recording medium. This is especially significant for magnetic cards used as recording media because they are frequently no longer flat as a consequence of their use and because of the characters occasionally imprinted on them.
A device for pressing magnetic read/write heads, separate for each magnetic track, of a multiple magnetic head against a magnetic card in motion relative to it is disclosed in British Patent Specification No. 2,115,597. In this prior device, each individual read/write head is equipped with a groove in which a pressure lever is fastened. This pressure lever is designed as a sheet-metal strip running in the direction of movement of the recording medium with a flat extension parallel to the plane of the recording medium. In the vicinity of its open end it is equipped with a bore with which it is pivoted on a pin. In the immediate vicinity of the read/write head, an oblong slot is provided in the pressure lever running in the direction of the recording medium with which the pressure lever is displaceably directed in the read/write head's direction of pressure in order to limit the motion of the read/write head at right angles to the direction of movement of the recording medium. The pressure lever is loaded in the direction of the recording medium with a leaf-type spring with the point of load application being in the vicinity of the read/write head. The open end of the leaf-type spring is shaped as a convex semicircle and, ideally, presses axially upon the pressure lever with a hemispherical, crater-shaped angle of elevation centrally located at the head. Thus, the pressure lever is stressed at points along its longitudinal axis in order to allow for certain mobility of the read/write head around the pressure lever's longitudinal axis. This freedom of movement of the read/write head is desired so that it can also adapt to the surfaces of recording media that may be curved at right angles to its direction of movement. On the other hand, this desired freedom of movement necessitates that either the pressure lever be pivoted with some play or be led to the guide pin with play in order to avoid its tilting as much as possible. However, this has the disadvantage that the pressure lever and thus also the magnetic read/write head in the direction of movement of the recording medium as well as at right angles to the direction of movement of the recording are inaccurately guided.